I'm running Mavericks and I've installed the xcode command line tools and the nomad-cli gem. It looks like every binary from the library is working except cupertino. Every other binary returns its 'help' command. But the iOS binary simply returns nothing.
If it's an issue -- I'm using RVM and I had the same issue with 1.9.3 and 2.1.0. The binary is located here on my system:
→ which ios
I must have some sort of naming conflict with 'ios' elsewhere in my environment. I simply copied jim:~/Documents/Xcode
→ cp /Users/jim/.rvm/gems/ruby-2.1.0/bin/ios /Users/jim/.rvm/gems/ruby-2.1.0/bin/cupertino
... (expected output)